Stretcher-rolls.



J. P. HEDSTROM.

STRETGHER ROLLS.

APPLICATION FILED NOV. 9, 1909.

1,038,127, Patented Sept. 10,1912.

2 SHEETS-SHEET 1.

WITNESSES: INVENTOR QBNQLM. BY

COLUMBIA PLANOGRAPH 60-, WASHKNUTON. D. c

J. P. HEDSTROM.

STRETGHER ROLLS.

APPLIGATION FILED NOV. 9, 1909.

1,038,127. Patented Sept. 10,1912.

2 SHEETS-SHEET 2.

WITNESSES: INVENTOR Aa ATTORNEY COLUMBIA PLANDGRAPH' 50-, WASHINGTON. D.c.

UNITED STATES PATENT OFFICE...

JOHN P. HEDSTROM, 0F BIG RAPIDS, MICHIGAN, ASSIGNOR 'I'O HANCI-IET'I.SWAGE WORKS, OF BIG RAPIDS, MICHIGAN, A CORPORATION OF MICHIGAN.

STRETCHER-ROLLS.

T 0 all whom it may concern:

Be it known that I, JOHN P. HEDsTRo-M, a citizen of the United States,residing at Big Rapids, in the county of Mecosta and skilled in the artto which it appertains to make and use the same.

This invention relates to stretching rolls for stretching band saws andthe like and pertains more particularly to combined stretching andshearing rolls, the object of the invention being to combine with astretching roll a shearing device that will not in any way interferewith the tensioning device, and to make a shear that will shear theblade straight across without having any tendency to wedge the saw inbetween the rolls.

I-Ieretofore the rolls for tensioning the saw have been used to acertain extent for also shearing the saw blade, but the tensioning rollshave not been entirely satisfactory for shearing purposes, because theuse of the tensioning rolls for shearing is liable to inj ure them fortensioning purposes. For this reason some types of tensionin machinesare provided with an extra set or rolls to be used for shearing only.

It is customary to form the rolls used for tensioning the saws, bygrinding the tensioning treads slightly rounding so that they present aslightly crowning surface to the saw. l/Vhen such tensioning rolls are.used for shearing, it has been customary to move one roll past the otherby sliding it along its arbor so as to bring the edges opposite eachother to make a cutting edge. Because of the fact that the tensioningrolls are crowned, presenting a somewhat conical rather than acylindrical surface to the saw, there is more or less tendency to bendthe saw instead of shearing it, thus tending to wedge the saw blade inbetween the rollers when the upper roll is forced down past the edge ofthe lower roll, the saw being presented to the cutting edges of therolls so as to lie at a slight angle to the axes of the rolls instead ofparallel with the axes of the rolls as it should do in order to producea clean shearing out without bending the blade. This action of thecrowned rolls Specification of Letters Patent.

Application filed November 9, 1909.

Patented Sept. 10, 1912.

Serial N0. 527,017.

' crumbles the edges of the rolls and spoils them both for tensioningand shearing. I avoid these diflicult-ies and produce a combinedtensioning and shearing roll by the means illustrated in theaccompanying drawings, in which Figure 1 illustrates part of astretching machine with the rolls in place; Fig. 2 shows the relativepositions of the rolls and saw when the rolls are adjusted forstretching;

and Fig. 3 shows the same rolls adjusted longitudinally for shearing,but having their axes separated, for the purpose of better illustration.Fig. 4 is a detail of the device for accomplishing the shearing.

1 is the upper roll, 2 the lower roll, and 3 the saw being operatedupon.

4 is the arbor of the upper roll and 5 the "arbor of the lower roll.

1 is the crowned stretching tread of the upper roll, and 2 of the lowerroll. In my improved construction I provide an extension 1 at one sideof the upper roll, and a similar extension 2 at the opposite side of thelower roll, these extensions having their outer corners 1 and 2extending radially out nearly as far as the crowns l and 2 that do thetensioning. As shown in Fig. 2, these extending corners do not interferein any way with the tensioning of the saw, and as shown in Fig. 3 theymake a properly formed shear for shearing the blade straight throughwithout any tendency to wedge the saw in between the rolls.

I have illustrated in Fig. 3 the arbors 4E and 5 as being supportedsufliciently to permit the plate 3 to pass through the rolls withoutshearing. It will be understood, however, that suitable means is to beprovided to move the arbors 4i and 5 closer together to bring theshearing corners of the rolls into shearing action and also to provideforsliding one of the rolls lengthwise on its shaft to change therelative positions of the rolls from that shown in Fig. 2 to that shownin Fig. 3. One means of accomplishing this result is illustrated in Fig.4:, where 6 is a guide provided on the frame of the machine and carryinga sliding block 7 upon which is adjustably supported a housing 8 thatsupports the arbor 4;. The housing 8 and the arbor 4: are raised andlowered by means of the screw 9 threaded in the block 7 and swiveled inthe housing 8. The screw 9 is operated by a handle 10. To

suitably guide the housing 8, a pair of rods 11 are fixed to the housing8 and pass loosely through holes in the block 7. The rods are fixed attheir upper ends to a cross-bar 12 through which the screw 9 passes.When screw 9 is turned it lowers or raises shaft 4, bringing theextensions 1 and 2 into shearing engagement or separating them, as maybe desired. It will be understood, however, that the particularmechanism shown in Fig. 4 is merely one embodiment of means foradjusting the distance between the arbors 4; and 5. The rolls arerevolved by means of the arbors 4 and 5, which in turn may be driven byany suitable means (not shown).

To further assist in producing a perfectly smooth square cut, I relievethe periphery of each of the extensions 1", 2 by forming the rolls withslightly decreasing diameters as at 1 and 2, thereby producing a slightrearward clearance between the roll and the saw just back of the cuttingedge. In addition to these clearances 1 and 2 I provide clearancegrooves or recesses 1 and 2 to separate the stretching treads from theshearing treads.

With this improved construction, one roll provides a satisfactory crownfor tensioning the saw the same as hertofore, and provides on the sameroll means for shearing the blade, the shearing means being entirelyindependent of the tensioning part of the rolls so that even if theshearing corners 1 and 2 become injured there still remains a perfeetroll for tensioning the saw. Furthermore, the stretching treads act asguides to assist in properly passing the material through theshearingtreads, and the shearing treads also serve as guides to steadythe material when the stretching treads are used. This improved roll iseven less expensive to manufacture than the plain stretching roll now incommon use, there being less material to be cut away in forming theroll.

What I claim as my invention and desire to secure by Letters Patent, is

l. A combined tensioning and shearing device comprising a pair ofrevolubly mounted rolls each having a crowned stretching tread, and ashearing tread formed integral with the roll at one end thereof, one ofsaid rolls being axially ad justable with relation to the other roll.

2. A combined tensioning and shearing device comprising a pair ofrevolubly mounted rolls each having a crowned stretching tread, and ashearing tread formed integral with the roll at one end thereof, one ofsaid rolls being axially adjustable with relation to the other roll, therear part of the shearing tread of each roll being of slightly reduceddiameter.

3. A combined tensioning and shearing device comprising a pair ofrevolubly mounted rolls each having a crowned stretching tread, and ashearing tread formed integral with the roll at one end thereof, one ofsaid rolls being axially adjustable with relation to the other roll,said roll being formed with a clearance groove between the stretchingtread of each roll and the tensioning tread.

In testimony whereof, I aflix my signature in presence of two witnesses.

JOHN P. HEDSTROM.

Witnesses:

E. D. SANFORD, H. J. HEYDENBURG.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

